1. Field of the Invention
The present invention relates generally to implements powered by v-belts and more specifically to sheaves which are used with v-belt drives.
2. Description of the Related Art
Earth working implements such as rotary tillers are frequently utilized with vehicles such as Lawn and Garden Tractors. It is common for such tractors to power these implements through engine-driven V-belt and sheave arrangements. Generally the sheaves are located beneath the tractor or vehicle with the belt drives extending from the engine, beneath the tractor, and to the driven sheaves of the attached implement.
Earth working implements frequently utilize rotating tines or knives to contact, penetrate, dig, turn and work the soil as the tractor and implement are advanced over the soil. Accordingly, the soil and other materials can be thrown by the rotating tines and contact the sheaves and/or belts of the drive arrangement. As this soil and foreign material contacts the sheaves, it may accumulate in the v-shaped grooves of the sheaves and become packed by the pressure exerted by the v-belt. If these implements are operated in wet soil conditions or a type of soil that does not easily fracture and break apart, there is a greater likelihood that the accumulated soil will become packed in the v-groove of a sheave.
Additionally contributing to the problem is the fact that vehicles used with these types of implements are typically smaller and have a low clearance beneath their frames where the sheave and belt drive arrangement is located. The belts and sheaves therefore operate in close proximity to the soil being worked. Further, in wet or muddy soil conditions, the tractor wheels may sink into the soil with the sheaves and belts of the drive arrangement passing into and through the soil, further increasing the likelihood that soil will accumulate in the v-groove of the sheave. When the tractor and implement are operated over uneven ground, the sheaves can also be forced to pass through clumps of soil.
When material does accumulate in the v-groove, a loss of traction between the belt and sheave can occur with an accompanying loss of power to the implement.
In an attempt to prevent soil and other materials from accumulating in the sheaves, guards have been placed adjacent to the sheave v-grooves. While these guards may serve to prevent the entry of some soil into the v-groove, they can not stop all material from entering the groove nor can they act to effectively remove material that does accumulate in the v-groove.